from __future__ import annotations

import json
from collections import defaultdict, deque
from typing import Any, Optional

from django.apps import apps
from django.contrib.contenttypes.models import ContentType
from django.db import models
from django.http import HttpRequest
from django.urls import NoReverseMatch
from django.utils.encoding import force_str
from django.utils.translation import (
    get_language,
    gettext,
    override as force_language,
)
from sekizai.context import SekizaiContext
from sekizai.helpers import get_varname

from cms.constants import PLACEHOLDER_TOOLBAR_JS, PLUGIN_TOOLBAR_JS
from cms.models import CMSPlugin, PageContent, Placeholder
from cms.utils.compat.warnings import RemovedInDjangoCMS51Warning
from cms.utils.conf import get_cms_setting
from cms.utils.urlutils import admin_reverse


def get_placeholder_toolbar_js(placeholder: Placeholder, allowed_plugins: Optional[list[str]] = None) -> str:
    label = placeholder.get_label() or ''
    help_text = gettext(
        'Add plugin to placeholder "%(placeholder_label)s"'
    ) % {'placeholder_label': label}

    data = {
        'type': 'placeholder',
        'name': force_str(label),
        'placeholder_id': str(placeholder.pk),
        'plugin_restriction': allowed_plugins or [],
        'addPluginHelpTitle': force_str(help_text),
        'urls': {
            'add_plugin': admin_reverse('cms_placeholder_add_plugin'),
            'copy_plugin': admin_reverse('cms_placeholder_copy_plugins'),
        }
    }
    return PLACEHOLDER_TOOLBAR_JS % {'pk': placeholder.pk, 'config': json.dumps(data)}


def get_plugin_toolbar_info(plugin: CMSPlugin, children: Optional[list[str]] = None, parents: Optional[list[str]] = None) -> dict[str, Any]:
    data = plugin.get_plugin_info(children=children, parents=parents)
    help_text = gettext(
        'Add plugin to %(plugin_name)s'
    ) % {'plugin_name': data['plugin_name']}
    data.update({
        "onClose": False,
        "addPluginHelpTitle": force_str(help_text),
        "plugin_order": '',
        "plugin_restriction": children or [],
    })
    return data


def get_plugin_toolbar_js(plugin: CMSPlugin, children: Optional[list[str]] = None, parents: Optional[list[str]] = None) -> str:
    data = get_plugin_toolbar_info(
        plugin,
        children=children,
        parents=parents,
    )
    return PLUGIN_TOOLBAR_JS % {'pk': plugin.pk, 'config': json.dumps(data)}


def get_plugin_tree_as_json(request: HttpRequest, plugins: list[CMSPlugin]) -> str:
    import warnings

    warnings.warn("get_plugin_tree_as_json is deprecated. Use get_plugin_tree instead.",
                  RemovedInDjangoCMS51Warning, stacklevel=2)
    return json.dumps(get_plugin_tree(request, plugins)[0])


def create_child_plugin_references(plugins: list[CMSPlugin]) -> deque[CMSPlugin]:
    """Creates the ``child_plugin_instances`` attribute on each plugin instance after downcasting."""
    plugin_children = defaultdict(deque)
    root_plugins = deque()

    plugin_ids = frozenset(plugin.pk for plugin in plugins)

    for plugin in reversed(plugins):
        plugin.child_plugin_instances = plugin_children[plugin.pk]

        if plugin.parent_id in plugin_ids:
            plugin_children[plugin.parent_id].appendleft(plugin)
        else:
            root_plugins.appendleft(plugin)
    return root_plugins


def get_plugin_tree(
    request: HttpRequest,
    plugins: list[CMSPlugin],
    restrictions: Optional[dict] = None,
    target_plugin: Optional[CMSPlugin] = None,
) -> dict[str, Any]:
    """
    Constructs a tree structure of CMS plugins for the toolbar.

    Args:
        request (HttpRequest): The HTTP request object.
        plugins (list[CMSPlugin]): A list of CMSPlugin instances to be organized into a tree.
        restrictions (Optional[dict], optional): A dictionary of plugin restrictions. Defaults to None.
        target_plugin (Optional[CMSPlugin], optional): The target plugin to render.
            Content will only be rendered if given. Defaults to None.

    Returns:
        tuple[dict[str, Any]]: A dictionary with up to five keys:
            - 'html': A string of rendered HTML for the plugin tree.
            - 'plugins': A flat list of plugin information dictionaries.
            - 'content': The rendered content of target_plugin (if given) including its children
            - 'target_position': The position of the target_plugin (if given)
            - 'target_placeholder_id': The placeholder id of the target_plugin (if given)
    """
    from cms.utils.plugins import downcast_plugins, get_plugin_restrictions

    tree_data = []
    tree_structure = []
    restrictions = restrictions or {}
    toolbar = get_toolbar_from_request(request)
    template = toolbar.templates.drag_item_template
    get_plugin_info = get_plugin_toolbar_info
    placeholder = plugins[0].placeholder
    copy_to_clipboard = placeholder.pk == toolbar.clipboard.pk
    plugins = list(downcast_plugins(plugins, select_placeholder=True))
    root_plugins = create_child_plugin_references(plugins)

    def collect_plugin_data(plugin):
        child_classes, parent_classes = get_plugin_restrictions(
            plugin=plugin,
            restrictions_cache=restrictions,
        )
        plugin_info = get_plugin_info(
            plugin,
            children=child_classes,
            parents=parent_classes,
        )

        tree_data.append(plugin_info)

        for plugin_instance in plugin.child_plugin_instances:
            collect_plugin_data(plugin_instance)

    with force_language(toolbar.toolbar_language):
        for root_plugin in root_plugins:
            collect_plugin_data(root_plugin)
            context = {
                'plugin': root_plugin,
                'request': request,
                'clipboard': copy_to_clipboard,
                'cms_toolbar': toolbar,
            }
            tree_structure.append(template.render(context))
    tree_data.reverse()

    content = {}
    # Render the target plugin if given and all plugins are local
    if target_plugin and all(plugin.get_plugin_class().is_local for plugin in plugins):
        # Also provide the parent plugin to the context (if available)
        downcasted = next(
            (plugin for plugin in plugins if plugin.pk == target_plugin.pk), None
        )
        parent = next(
            (plugin for plugin in plugins if plugin.pk == target_plugin.parent_id), None
        ) if target_plugin.parent_id else None
        content["content"] = get_plugin_content(request, downcasted, {"parent": parent})

    return {'html': '\n'.join(tree_structure), 'plugins': tree_data, **content}


def get_plugin_content(request: HttpRequest, plugin: CMSPlugin | list[CMSPlugin], context: dict = None) -> dict[str, Any]:
    if context is None:
        context = {}
    plugin_list = plugin if isinstance(plugin, list) else [plugin]
    toolbar = get_toolbar_from_request(request)
    renderer = toolbar.content_renderer
    # Switch to edit mode despite the request originally coming from the admin
    toolbar.edit_mode_active = True
    renderer._placeholders_are_editable = True
    context = SekizaiContext({'request': request, **context})
    try:
        return [{
            "html": renderer.render_plugin(plugin, context, placeholder=plugin.placeholder, editable=True),
            "js": "".join(context[get_varname()].get("js", [])),
            "css": "".join(context[get_varname()].get("css", [])),
            "position": plugin.position,
            "placeholder_id": plugin.placeholder_id,
            "pluginIds": get_plugin_tree_ids(plugin),
        } for plugin in plugin_list]
    except Exception:
        return []  # do not deliver content if rendering fails



def get_plugin_tree_ids(plugin: CMSPlugin) -> list[int]:
    plugin_ids = [plugin.pk]
    for child in plugin.child_plugin_instances or []:
        plugin_ids += get_plugin_tree_ids(child)
    return plugin_ids


def get_toolbar_from_request(request: HttpRequest):
    from .toolbar import EmptyToolbar

    return getattr(request, 'toolbar', EmptyToolbar(request))


def add_live_url_querystring_param(obj: models.Model, url: str, language: Optional[str] = None) -> str:
    """
    Append a live url to a given object url using a supplied url parameter configured
    by the setting: CMS_ENDPOINT_LIVE_URL_QUERYSTRING_PARAM

    :param obj: Placeholder source object
    :param url: Url string
    :param language: The current language code or None
    :returns: A url string
    """
    url_param = get_cms_setting('ENDPOINT_LIVE_URL_QUERYSTRING_PARAM')
    if not hasattr(obj, "get_absolute_url"):
        return url
    try:
        live_url = obj.get_absolute_url()
    except NoReverseMatch:
        return url
    url_fragments = url.split('?')
    if len(url_fragments) > 1:
        url += f'&{url_param}={live_url}'
    else:
        url += f'?{url_param}={live_url}'
    return url


def get_object_edit_url(obj: models.Model, language: str = None) -> str:
    """
    Returns the url of the edit endpoint for the given object. The object must be frontend-editable
    and registered as such with cms.

    If the object has a language property, the language parameter is ignored.
    """
    content_type = ContentType.objects.get_for_model(obj)

    language = getattr(obj, "language", language)  # Object trumps parameter
    if language is None:
        language = get_language()

    with force_language(language):
        url = admin_reverse('cms_placeholder_render_object_edit', args=[content_type.pk, obj.pk])
    if get_cms_setting('ENDPOINT_LIVE_URL_QUERYSTRING_PARAM_ENABLED'):
        url = add_live_url_querystring_param(obj, url, language)
    return url


def get_object_preview_url(obj: models.Model, language: str = None) -> str:
    """
    Returns the url of the preview endpoint for the given object. The object must be frontend-editable
    and registered as such with cms.

    If the object has a language property, the language parameter is ignored.
    """
    content_type = ContentType.objects.get_for_model(obj)

    language = getattr(obj, "language", language)  # Object trumps parameter
    if language is None:
        language = get_language()

    with force_language(language):
        url = admin_reverse('cms_placeholder_render_object_preview', args=[content_type.pk, obj.pk])
    if get_cms_setting('ENDPOINT_LIVE_URL_QUERYSTRING_PARAM_ENABLED'):
        url = add_live_url_querystring_param(obj, url, language)
    return url


def get_object_structure_url(obj: models.Model, language: str = None) -> str:
    """
    Returns the url of the structure endpoint for the given object. The object must be frontend-editable
    and registered as such with cms.

    If the object has a language property, the language parameter is ignored.
    """

    content_type = ContentType.objects.get_for_model(obj)

    language = getattr(obj, "language", language)  # Object trumps parameter
    if language is None:
        language = get_language()

    with force_language(language):
        return admin_reverse('cms_placeholder_render_object_structure', args=[content_type.pk, obj.pk])


def get_object_for_language(obj: models.Model, language: str, latest: bool = False) -> Optional[models.Model]:
    """
    Retrieves the correct content object for the target language. The object must be frontend-editable
    and registered as such with cms.

    Two cases have to be distinguished:

    1. **Object has a language property:** If the language of the passed object is different,
       sibling objects are retrieved from the database and cached in the object passed.
    2. **Object has no language property:** The placeholders of the object contain the different
       language content. The object itself is returned
    """
    if getattr(obj, "language", language) == language:
        # Object does not have language field or language is requested language
        # Return object itself
        return obj
    if isinstance(obj, PageContent):
        return obj.page.get_admin_content(language, fallback=False) or None
    # Does the object have a cache with sister objects
    cached_object = getattr(obj, "_sibling_objects_for_language_cache", {})
    if cached_object:
        return cached_object.get(language)

    extension = apps.get_app_config('cms').cms_extension
    model = obj.__class__
    field = extension.model_groupers.get(model)
    if not field:
        # Cannot infer sister object if grouper field is unknown
        return None
    # Grouper model not registered or does not have a get_content_obj method,
    # or get_content_obj does not accept language parameter
    # Now query db
    grouper_filter = {field: getattr(obj, field)}
    qs = model.admin_manager.latest_content() if latest and hasattr(model, "admin_manager") else model.objects
    obj._sibling_objects_for_language_cache = {
        result.language: result for result in qs.filter(**grouper_filter)
    }
    return obj._sibling_objects_for_language_cache.get(language)
